As is generally known, boring is a mechanical process for machining surfaces of revolution carried out by one or more cutting tools. Boring machines used for performing such operations typically allow the fitting of various types of tools to permit the performance of other operations, such as drilling, milling, thread-cutting, etc.
Depending on the position of the shaft/arbor, such boring machines may be horizontal or vertical, and boring may be cylindrical, conical, radial or spherical, enabling internal conical or cylindrical surfaces to be obtained in spaces that are normally difficult to access. Such boring may utilize axes that are perfectly parallel to one another, by means of the positioning of the machining tool by means of adjustment of the headstock to a specific height and the platen in a transverse position, all the displacements being indicated on graduated scales by means of optical reading equipment or analog/digital counters.
Therefore, for such boring operations, use is made of boring tools selected as a function of the dimensions and characteristics of the operation (i.e., length and diameter). The tools commonly have small dimensions since they operate inside bores previously made by boring bits, such as the boring bar, which, in turn, has to be rigid, cylindrical and with no rectilinearity defect, affording correct positioning on the shaft/arbor for the mounting of bushes that form bearings, thereby preventing possible deflections and vibrations.
Such boring bars incorporate interchangeable tips and micrometric adjustment systems for increasing the depth of the tool in the workpiece, thus permitting better finishing and cylindricity conditions. Such adjustment systems may include adjustment cartridges that allow precise boring within tolerance requirements.
However, conventional adjustment cartridges do not afford sufficient precision and allow coarse adjustment (i.e., the resolution of the apparatus allows increments of 0.010 mm in terms of the radius).
A further drawback lies in the fact that conventional cartridges require auxiliary equipment for making the adjustment of the measurement, thereby increasing the adjustment time.
Yet another drawback lies in the fact that conventional cartridges have a locking screw, enabling the apparatus to be unusable on account of damage caused to the adjustment mechanism during performance of the operation when carried out by an untrained technician.